The Virology Laboratory Core provides virologic, immunologic, and molecular laboratory testing for HSV and HIV in 3 well established, accredited diagnostic laboratories; each directed by University of Washington (UW) faculty involved in this Program Project: the UW Virology Laboratory at Children's Hospital and Medical Center (CHMC; directed by Dr. R Ashley), the UW Retrovirology Laboratory at University of Washington Health Sciences Center (directed by Drs. R. Coombs and L. Corey)) and the Molecular Virology Laboratory at the Fred Hutchinson Cancer Research Center (FHCRC; directed by Dr. L. Corey). The CHMC lab will perform HSV isolation, serology, and antiviral sensitivity testing to diagnose and characterize HSV infections in subjects enrolled in Project I-IV. The UW Retrovirology Lab will perform HSV PCR, in situ HSV PCR< and HSV restriction enzyme analyses. Lab testing at these 3 sites will be supplemented by specialized testing performed in the research laboratories of Dr. R. Ashley at CHMC (mucosal antibody testing) and Dr. D. Koelle at FHCRC (CD8+ pCTL testing). Testing performed in these 5 sites will follow uniform practices of quality assurance and quality control which are established and reviewed biannually by the College of American Pathologists for accreditation of our diagnostic testing services. Accesioning of specimens, specimen handling and banking, specimen retrieval, and reporting will be performed according to uniform guidelines to assure accurate test results as well as smooth electronic data transfer between laboratories and the data management team; between laboratories and investigators involved in Projects I-IV, and between data management and the Administrative Core.